> On Oct 26, 2020, at 23:46, Hans de Goede <hdegoede@xxxxxxxxxx> wrote:
>
> The i2c-hid driver would quietly fail to probe the i2c-hid sensor-hub
> with an ACPI device-id of SMO91D0 every other boot.
>
> Specifically, the i2c_smbus_read_byte() "Make sure there is something at
> this address" check would fail every other boot.
>
> It seems that the BIOS does not properly reset/power-cycle the device
> leaving it in a confused state where it refuses to respond to i2c-xfers.
> On boots where probing the device failed, the driver-core puts the device
> in D3 after the probe-failure, which causes the probe to succeed the next
> boot.
>
> Putting the device in D3 from the shutdown-handler fixes the sensors not
> working every other boot.
>
> This has been tested on both a Lenovo Miix 2-10 and a Dell Venue 8 Pro 5830
> both of which use an i2c-hid sensor-hub with an ACPI id of SMO91D0.
>
> Note that it is safe to call acpi_device_set_power() with a NULL pointer
> as first argument, so on none ACPI enumerated devices this change is a
> no-op.
>
> Cc: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Acked-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
And I do wonder if we should do this for all ACPI devices...
Kai-Heng
> ---
> Changes in v2:
> -Rebase on 5.10-rc1
> ---
> drivers/hid/i2c-hid/i2c-hid-core.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
> index 786e3e9af1c9..aeff1ffb0c8b 100644
> --- a/drivers/hid/i2c-hid/i2c-hid-core.c
> +++ b/drivers/hid/i2c-hid/i2c-hid-core.c
> @@ -943,6 +943,11 @@ static void i2c_hid_acpi_enable_wakeup(struct device *dev)
> }
> }
>
> +static void i2c_hid_acpi_shutdown(struct device *dev)
> +{
> + acpi_device_set_power(ACPI_COMPANION(dev), ACPI_STATE_D3_COLD);
> +}
> +
> static const struct acpi_device_id i2c_hid_acpi_match[] = {
> {"ACPI0C50", 0 },
> {"PNP0C50", 0 },
> @@ -959,6 +964,8 @@ static inline int i2c_hid_acpi_pdata(struct i2c_client *client,
> static inline void i2c_hid_acpi_fix_up_power(struct device *dev) {}
>
> static inline void i2c_hid_acpi_enable_wakeup(struct device *dev) {}
> +
> +static inline void i2c_hid_acpi_shutdown(struct device *dev) {}
> #endif
>
> #ifdef CONFIG_OF
> @@ -1175,6 +1182,8 @@ static void i2c_hid_shutdown(struct i2c_client *client)
>
> i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
> free_irq(client->irq, ihid);
> +
> + i2c_hid_acpi_shutdown(&client->dev);
> }
>
> #ifdef CONFIG_PM_SLEEP
> --
> 2.28.0
>
